This invention relates to a system and method for detection and identification of luminescent organic particulates or films on devices and, more particularly, to the detection and/or identification of these particulates or films during the manufacture of semiconductor devices.
A major problem in the manufacture of semiconductor devices has always been the presence of extraneous particulate matter in active areas. These have caused defects affecting yields, reliability and performance.
In the past, each semiconductor chip contained only one or, at most, two active devices and thus required large scale production of identical chips. The active geometries were fairly large and only occupied a small portion of the available area or commonly called real estate of a chip. Defect-causing particles were in the hundredths of a millimeter size range and the probability of their being in a critical region was low. In addition, while the cost per circuit was relatively high, the cost per chip was not. Because of all these factors, the economic impact of particulates was not very great.
Today, the dimensions of the active devices have been reduced and their number per chip have been increased by orders of magnitude thereby increasing the useable real estate on a chip by multilevel interconnections of narrower conductors. The production of these large scale integrated (LSI) chips is small relative to the past single device to the large scale production of many small volume chips and, while the cost per device or circuit has been drastically reduced, the cost per chip has increased sharply. Accordingly, the economic impact of defects caused by particulate contamination has become significant because a particle as small as a submicron can make an entire chip unuseable.
In some cases, the mere detection of the particulates during manufacturing is sufficient so as to monitor the contaminate level and if it exceeds a certain level to stop the manufacturing lines. In other cases, this detection must be followed by an identification of the particulate material so that its source may be found and proper corrective actions instituted to prevent its reoccurrence.
While a number of detection systems and analytical tools are available, they do not permit either on-line detection and identification or organic particles or film or even rapid off-line identification. In addition, the analytical tools require a destructive test.